Remove g_type_init() calls

Very many testcases, some GLib tools (resource compiler, etc) and
GApplication were calling g_type_init().

Remove those uses, as they are no longer required.

https://bugzilla.gnome.org/show_bug.cgi?id=686161

gio/tests/sleepy-stream.c

@@ -285,7 +285,6 @@ main (int argc, char **argv)
   g_test_init (&argc, &argv, NULL);
   g_test_bug_base ("http://bugzilla.gnome.org/");
 
-  g_type_init ();
   g_test_add_func ("/filter-stream/input", test);
   g_test_add_func ("/filter-stream/async", asynch);